INTRODUCTION. The Clinical Core (Core C) will support the two clinical projects, Projects 1 and 2. For both UCSF and Mayo sites, Core C will be responsible for (1) a sample repository, including storage and appropriate distribution of all biologic specimens, (2) establishing and managing a web-entry central database, (3) establishing the pre-test probability of any Transfusion Related Acute Lung Injury (TRALI) based on a post hoc expert review of radiology and clinical data, (4) providing laboratory facilities and personnel for HLA antigen/antibody testing of donor and recipient plasma, and finally (5) ensuring data safety and monitoring aspects of the research so as to conform to Good Clinical Practice and to NHLBI and local IRB guidelines.